Even though neurofibromatosis ( NF) is not a rare neurological disorder, but there is few studies regarding the relationship between NF and psychological disorders. A 14 year old girl with NF type 1 associated with multiple cerebral lesions was admitted in psychiatric ward due to restlessness , hypertalktiveness aggressive behavior, and flight of idea. Psychiatric diagnosis, based on DSM IV was bipolar mood disorder ( Manic phase). Coincidental occurrence of mania and NF type I with cerebral involvement in a patient is spares and despite of absence of reports about classical mania in patients with NF type I, the possibility of secondary mood disorder followed by primary neurological disorder is discussed.